Slots developers keep coming up with new special features designed to provide additional win opportunities and make gameplay more dynamic.

Some of these innovations prove to be an instant success but, at the same time, the online gaming community still loves features incorporated in titles that were released ages ago.

That’s why we decided to compile a list of our favorite bonus rounds and explain why players are so eager to spin reels of these particular online slots.

Thunderkick’s Fruit Warp looks nothing like a standard slot. Instead of symbols neatly arranged in columns and rows, one sees nine pieces of fruit floating in mid-air in no particular order. Players win by landing at least 3 matching ones while 4 prompts a re-spin of all other symbols and 5+ trigger the corresponding Fruit Mode.

During the bonus round, each symbol matching that Fruit Mode activates 1 step in the Warp Meter and initiates a re-spin. Some steps contain multipliers or extra lives.

Multipliers increase in value with each win depending on the number of winning symbols. Once they’re activated, their value will be locked.

The bonus round lasts for as long as new fruits matching the triggered mode land on reels and extra lives are spent to compensate for spins that fail to deliver that particular symbol.

The RTP is high at 97% and max payout 11,000x the stake.

Fat Rabbit by Push Gaming plays on a 5×5 reel area, offers a return of 96.45% and a maximum payout of 2,000x the bet. Randomly triggered Harvest Feature sends a tractor plowing through the reels and adding random Wild Carrots in the process.

If Wild Carrot and Wild Rabbit appear simultaneously, they’ll trigger the Free Spins bonus round. Wild Rabbit stays on the reels and moves only to devour Carrots which happen to land during the feature.

The meter at the bottom of the screen fills with each eaten Carrot and, once it’s full, causes the Rabbit to grow and grant additional spins.

The number of free games starts at 5 but, thanks to the fattening Rabbit, it can increase to 20. It takes 15 Carrots to get there and at that point, the Rabbit will be 5×5 in size.

Reactoonz from Play ‘n GO plays on a 7×7 grid filled with friendly-looking aliens. A group of 5 or more identical ones will pay and initiate a cascade.

Any non-winning spin can prompt the Gargantoon to drop 4-10 Wilds onto the grid.

In addition to features triggered by various events (3×3 Wilds, extra substitutes, symbol transformation), the game incorporates a highly lucrative bonus round.

The container to the right of the reels, also known as Quantum leap, charges with each payout.

After you win on 25 symbols, one of the four Quantum features is randomly chosen and added to the queue. The fifth charge adds the Gargantoon feature.

A non-winning spin activates queued Quantum features and the bonus round ends once you use them all. This highly volatile game has an RTP of 96.00% and is willing to pay up to 4,570x your bet.

Jammin’ Jars is another excellent slot from Push Gaming which uses an 8×8 reel area and features cascading reels. Wild Jam Jar symbol moves to an adjacent position and increases its multiplier by 1 each time it contributes to a cluster win.

It will maintain its position during the cascade and hopefully help create significant payouts.

Jam Jars also represent Scatters which trigger the Free Games feature when in groups of 3.

Winning Jars continue to move to new positions, the same as during the base game. Any non-winning cascade can activate the Rainbow Feature which adds one or more giant fruit icons of the same type.

The theoretical return of this game is 96.83% and a top prize worth 20,000x the stake.

Immortal Romance, one of the most popular Microgaming titles, is a 243 ways-wins vampire-themed slot with randomly activated Wild Desire feature which turns up to 5 reels Wild. It takes a minimum of 3 Scatters to enter the Chamber of Spins and play Amber’s 10 Free Spins with all wins multiplied x5.

Multiple entries unlock further bonus features –Troy’s’ 15 Free Spins with Vampire Bats which randomly transform symbols into x2 or x3 multipliers (available from 5th retrigger), Michael’s 20 Free Spins with rolling reels and consecutive wins increasing the multiplier to up to x5 (available from 10th retrigger), and Sarah’s 25 Free Spins with Wild Wine which lands only on reel 3, randomly turns symbols into additional substitutes and awards extra spins on the house (available from 15th trigger).

Immortal Romance has an RTP 96.86% and can pay a maximum of 3,645,000 coins.

This romantic BTG title is a 4,096 ways-to-win slot with Angel Wilds able to boost the win by up to x144.

It takes 2 Scatters winning a Heart and at least 3 to trigger the feature with a choice of Be My Angel Free Spins and Dynamite Lover Free Spins.

The first awards 7 free games and reveals one symbol which becomes a Sticky Wild.

These persistent substitute icons award 3 extra spins when 3 show up in the same reel and transform into Angel Wilds when 4 lands of on reels 3 or 4. Angel Wilds have a multiplier which starts at x4 and increases by 2 with each spin up to a maximum of x12.

If you manage to collect 40 Hearts during the base game, you’ll win Heartstopper Enhanced Free Spins in which the Purple Heart becomes an additional Sticky Wild. The RTP is 96.43% and max win 40,960x the bet.

Kingmaker is one of BTG’s Megaways slots with up to 16,807 ways wins. It offers a theoretical payback of 96.65% and has a max win potential of 10,000x the stake. Colorful gems are high-paying icons, each with a multiplier starting at x1 and increasing with every five-of-a-kind gem win.

Land 3, 4 or 5 Scatters and you’ll get 7, 12 or 20 Free Spins with a win booster which equals the total of all individual gem multipliers.

Free Spins multiplier will further grow every time you win with 5 identical gems.

To retrigger the feature, 3+ Scatters have to appear while you’re still playing on the house. When the bonus round ends, all multipliers reset to x1.

Flame Dancer is an exotic piece from Novomatic with 5 reels, 20 variable pay lines and an RTP of 95.29%.

Wilds landing on reels 2 and 4 will fully expand and potentially help create multiple paying combos.

During the Free Spins bonus round, they will transform all high-paying symbols into substitute icons so you may get to see a screen filled with Wilds.

In order to make this possible, you’ll first have to land at least 3 Scatters depicted as flaming sticks and thus win 7 free games with additional Wild positions. Reels spinning for free while Wilds perform the transforming act cay easily result in a substantial feature win.

Blueprint Gaming took advantage of BTG’s popular Megaways mechanic to develop a slot with up to 15,625 ways to pay and an RTP of 96.50%.

All Mystery icons in view reveal the same regular symbol while Wild hammers trigger Lightning Strike which awards a re-spin with multiplier Wilds held in place.

After every win of 5x your bet or higher, you’ll be given an option to enter the Mega Spins Ladder and attempt to boost the win or exchange it for up to 25 Mega Spins with extra Wild and Mystery symbols.

If you choose to gamble, a wheel with red and green segments will spin to deliver one of two outcomes – a win plus a chance to gamble some more (green) or lose it all (red).

The risk may be worth taking owing to the top reward of 50,000x the bet.

Push Gaming makes it to top 10 once again thanks to Razor Shark, a maritime-themed slot with a return of 96.70% and wins potential of 50,000x.

Mystery Stacks covering 4 symbol positions trigger the Nudge & Reveal feature and reveal either Golden Sharks or one of the paying icons.

If Stacks transforms into Sharks, the Razor Reveal feature spins each symbol within the Stack and makes it land on a bet multiplier of up to x2,500 or Scatter.

The entire Stack nudges one position down with every spin and reveals a new symbol.

The Free Games feature is triggered by 3+ Scatters.

You’ll be playing with reels 2 and 4 filled with Mystery Stacks and all wins boosted by a multiplier which starts at x1 and increases with every activation of the Nudge & Reveals feature.

There’s no definite max number of Free Spins; feature ends once no Mystery Stacks are visible.